Pyrrole thioamide complexes of the d8 metals platinum(II), palladium(II) and gold(III)

Reactions of the cycloaurated gold(III) complexes [AuCl2(2-benzylpyridyl)] and [AuCl2 (C6H4CH2NMe2)] with a set of pyrrole-2-thioamide ligands, containing various substituents on the pyrrole ring, gave a series of new gold (III) pyrrole thioamide complexes. X-ray crystal structures on two complexes indicate that the pyrrole thioamide ligand is coordinated through the deprotonated pyrrole nitrogen, as well as the sulfur atom of the deprotonated thioamide group, forming five-membered chelate ring complexes. In both complexes, the two highest transinfluence donor atoms (C and S) are mutually cis. Related sets of platinum(II) and palladium(II) pyrrole thioamide complexes were similarly prepared by reactions of cis- [PtCl2(PPh3)(2)] and [PdCl2 (dppe)] (dppe = Ph2PCH2CH2PPh2)] respectively. The complexes were characterised by NMR and IR spectroscopies, and ESI mass spectrometry. A preliminary investigation of the activity of a selection of compounds towards A549 (adenocarcinomic human alveolar basal epithelial) cells was also carried out.